Originally Posted by Jewels
As for brake controller, I know even less. I don't know what the dealer has on hand. The brand I have heard here is "prodigy"? All I know is it is important that the braking system is variable rather than fixed?
I think what you are talking about here is time-delayed versus proportional controllers.
Time-delayed uses a fixed amount of braking power each time you brake. Of course this power is adjustable when you set up the brake controller, but you have to make sure you match the power well to your load. These type of controllers work pretty well if you are towing the same load all the time. What many do not like about the time delayed controllers that they can make the rig jerky at times or they don't send enough power in emergency braking situations because the power level is set when you first set up the controller. Here's an example.
You set up your controller and let's say power level 6 fits your load well for making smooth stops. Now you're going down the highway and a semi passes the other direction and your trailer starts to sway a bit. You lightly tap the brakes in your truck, but the controller stills send that level 6 power to the back which is too much for a light tap and the trailer jerks against the truck. On the other end, level 6 would not be enough if you have to suddenly hit the brakes hard. You have to reach down and use the manual override to get full power on the trailer brakes.
This is what makes a proportional controller such a pleasure to use. Depending on what model, a proportional controller will either have a pendulum or accelerometer inside. All the new high-end cell phones with touch screens that turn the display when you turn the phone use an accelerometer or gyrometer inside to detect the phone's position. These devices use simple physics to read how hard you are braking. The harder you brake the more the nose of the truck dips and you are pressed into your seat belt. A proportional controller uses one of these devices to detect this momentum.
Since the controller can now read that information, it can send a proportional amount of power to the brakes so the trailer brakes evenly with the truck. A light tap of the truck brakes lightly engages the trailer brakes, no jerking. On the other end, if you slam on the truck brakes, the controller will do the same for the trailer brakes.
A lot of people are used to time delayed so they continue to use them or they do not tow often enough or far enough that they want to spend the extra for a proportional. But those that try a proportional controller almost never go back. They really are a lot smoother.
The Prodigy line of controllers that you and powerboatr mentioned are proportional controllers and are used by a ton of towers. I hope I was able to clear up some brake controller questions for you. If you have more questions feel free to ask. I'm sure myself or one of the other users could help you out.